Use of a film with anchoring elements for a mechanic fixation

ABSTRACT

A method of nondestructive, reversible fixing of a coherent layer to a substrate, comprising the steps of anchoring a nonfibrous coherent layer to a film having either or both of projecting or embedded anchoring elements, wherein the anchoring elements provide mechanical anchorage of the coherent layer to the film, and fixing the coherent layer and film to the substrate. The coherent layer is anchored by applying a liquid or paste form material to the substrate that sets on the substrate to form the coherent layer, which is nonadhesive or only slightly adhesive to the film.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage application filed under 35U.S.C. § 371 of International Application No. PCT/EP00/05339, claimingpriority under 35 U.S.C. §§ 119 and 365 of PCT/EP00/05339, filed Jun. 9,2000, in the European Patent Office, and DE 199 27 790.7, filed Jun. 18,1999, in the German Patent Office.

This invention relates to the use of a film with anchoring elements formechanically fixing a coherent layer to a substrate.

One such use is known. Thus, DE 7029524 describes a device for fixingwall, ceiling, floor or other surface coverings which consists of anintermediate support with anchoring elements and of a nonwoven to whichnonfibrous covering materials, for example paper, plastic films, plasticmoldings, wood and metals, are fixed. This device has the majoradvantage that the connections can be easily and completely broken at acertain place. However, it also has the disadvantage that the joinedsubstrates are very difficult to reposition relative to one another.This applies in particular to substrates of large surface area. Inaddition, coverings which level out uneven surfaces are not possible.

Accordingly, the problem addressed by the present invention was to finda way of reversibly joining two substrates which would not have any ofthese disadvantages and which in addition would provide a compositematerial that would be able to withstand routine tensile shear stresseswhile allowing easy and almost complete separation. In addition, thesubstrates would be reusable after separation.

The solution to this problem as provided by the invention is defined inthe claims and is essentially characterized in that a fibrous layer isnot used for mechanical anchoring with the anchoring elements of a film.

DESCRIPTION OF THE INVENTION

According to the invention, a liquid substance is directly applied toand solidified on the film with the anchoring elements. Minimal adhesionshould occur between the film with the anchoring elements and thesolidified liquid substance. Cohesion should be largely provided by themechanical anchorage of the solidified liquid substance. In addition,tearing off of the anchoring elements during separation of thesolidified liquid substance from the film with the anchoring elementsshould largely be avoided by a suitable choice a) of deformablematerials and b) slidable forms of the anchoring elements. The anchoringelements should withstand separation without damage (see FIG. 1).

The present invention relates to the use of a film with projectingand/or embedded anchoring elements for mechanically fixing a coherentlayer to a substrate, the coherent layer being nonfibrous. The preferredembodiments can be found in the characterizing features of the claims.

The present invention also relates to a double-sided adhesive tape of afilm with anchoring elements on at least one side instead of anotherwise typical smooth film, a woven fabric or a nonwoven, theadhesion of the pressure sensitive adhesive layer of the film on oneside of the film being so low that it can be peeled off intact.

The present invention also relates to a film with embedded anchoringelements.

The present invention further relates to a velcro tape of elastomers,more particularly thermoplastic elastomers.

Films in the context of the invention are understood to be thin, flatflexible webs of metals, glass, ceramic and, above all, plastics. Theirthickness is preferably in the range from 0.04 to 2 mm. However, theymay also be considerably thicker in cases where the flexibility of thewebs and their ability to be rolled up easily are not importantcriteria. More particularly, moldings provided with anchoring elementsduring their actual production, for example plates or bars, may be used.

The surface of the film is appropriate and, in particular, may be roundor strip-like with a width of 0.2 to 1,000 and more particularly 1 to500 cm for a length of 0.05 to 5,000 and more particularly 0.1 to 4,000m. The film is generally compact, i.e. has no pores or holes or onlysmall pores or holes. The sum of the holes makes up at most 10% of thetotal surface area. The shape, size and number of holes should be suchthat, although the desired permeability to gases and vapors is achieved,none of the still liquid phase strikes through during the production ofthe coherent layer.

The material of the film is either metal or plastic, preferably plastic,more particularly a polyolefin, such as polyethylene or polypropylene,polyamide, polyvinyl chloride, a fluorine-containing polymer, siliconeor a polyurethane elastomer or utility articles coated therewith. In oneparticular embodiment, the films and anchoring elements consist of thesame material. However, they may also consist of a combination ofmaterials.

Corresponding films are known in large numbers. When choosing the film,the deformability and adhesion of the nonfibrous coherent layer shouldbe taken into consideration. Adhesion should be low and thedeformability of the anchoring elements and/or the nonfibrous coherentlayer should be so high that the anchoring elements largely retain theirfunction, i.e. are not tom off, during separation of the layers.

The low adhesion between the film and the nonfibrous coherent layer mayemanate from the nature of the materials used. However, it may also beobtained by a pretreatment before application of the liquid nonfibrouslayer, for example by spraying with water or by coating with wax orsimilar materials that are difficult to bond.

The deformability of the anchoring elements or the coherent nonfibrouslayer may also emanate from the nature of the materials used or may beattributed to physical measures, for example porosity.

The shape of the anchoring elements is of course also important. If, forexample, the nonfibrous coherent layer consists of a non-deformablematerial such as, for example, cement- or gypsum-based binders or atwo-component epoxide, the anchoring elements should be relativelyreadily deformable and elastic both in their constituent material and intheir shape, for example should consist of plastics, such as PE, PP,silicone or rubber.

One side of the film is generally smooth so that it may readily be fixedto the substrate either by a covered adhesive layer or by nails andscrews. It may also have anchoring elements on both sides, particularlywhen the substrate is fibrous or when the same adhesive is to be usedboth for fixing the film to the substrate and for fixing to thesubstrate.

The number of anchoring elements depends inter alia on the requiredlevel of adhesion and is generally between 0.1 and 2,000 and preferablybetween 1 and 500 g per cm².

The film has anchoring elements an at least one side. Their length is atleast 0.05 mm and preferably at least 0.2 mm and only rarely exceeds 10mm. The anchoring elements may be embedded In the film, but preferablyproject beyond the plane of the film. In the latter case, the film maybe a typical velcro tape, an antislip tape or a “stubble” film, forexample a flocked film. However, not all forms of anchoring elements oftypical velcro tapes are equally suitable. Thus, anchoring elements withundercuts (acute angle between pin and hook) or with loop-like spiralsor closed loops are unfavorable. The same applies to anchoring elementswith such an intensive anchoring effect that they are torn out duringseparation. Thus, in the case of a mushroom-shaped anchoring element,the cross-sectional diameter of the cap should be less than 10 times thevalue of the stalk of the mushroom. Anchoring elements with loops are ofcourse particularly unfavorable (see FIG. 2). The shapes of theanchoring elements are favorable when they allow sliding out from thecoherent layer without losing their function Or being torn off (see FIG.3). Particularly favorable forms are characterized in that the anglebetween the pin and the hook is 90° or larger (see FIG. 4). However, itmust be smaller than 180° because otherwise no hooking occurs unless thepin is oblique rather than vertical in relation to the film. If then thepins still point in different directions, they also effect anchorage ofthe nonfibrous coherence layer. In contrast to conventional velcrotapes, the anchoring elements or their pins may also form an angle ofless than 90° and preferably less than 45° to the film. Which angle isthe most favorable will depend inter alia on the deformability of thecoherent layer.

In general, the ends of the anchoring elements are not pin-like, butthickened (heads), angled or bent downwards (hooks) or flattened off(mushroom shape). FIGS. 1 a, 1 b and 1 c schematically illustrate thechange in the cross-sectional form of a readily deformable anchoringelement (1), a) during the first coating with the coherent layer, b)during its separation in the hardened state and c) before the secondcoating. The cap of the mushroom is deformed during separation. Recoverymay not be 100% (compare 1 c) with 1 a)).

FIGS. 2 a) to 2 f) show schematic cross-sections of the shapes ofanchoring elements which are unsuitable for nondestructive separation,even when the nonfibrous coherent layer is readily deformable. This isbecause they have undercuts (see 2 a) and 2 b)) or even loops (2 c), 2d) and 2 e)). The shape 2 f) is unfavorable on account of the size ratioof mushroom cap to mushroom stalk.

FIGS. 3 a), b), c), d) and e) are schematic cross-sections through theshapes of readily deformable anchoring elements which are favourable fornondestructive separation.

FIG. 4 is a schematic cross-section through a shape of an anchoringelement of a material that does not readily deform a) during coating andb) during separation.

FIG. 5 is a schematic cross-section through the film (2) with (a) onlyembedded anchoring elements and (b) a combination of embedded andprojecting anchoring elements.

Where the nonfibrous coherent layer is completely or substantiallynondeformable, the anchoring elements preferably consist of a materialwhich is barely deformable, if at all, in a thin layer of 0.05 to 10 mm.

The composite material produced in accordance with the inventionwithstands tensile stresses comparable with those known for theparticular application, but is weaker in its peel strength by a factorof at least 2 and preferably by a factor of >5 by comparison with peelstrengths on typical substrates without the film with anchoringelements. Accordingly, relatively little force has to be applied forseparation. Separation takes place specifically on the film, theanchoring elements remaining largely intact and being available forreuse.

-   -   Other advantages of the fixing according to the invention are:    -   repositionability of the substrates providing the nonfibrous        layer has not solidified,    -   substantially complete separation and    -   gap bridging at any level.    -   Leveling of uneven substrates is readily possible through the        variable thickness of the nonfibrous layer.

The nonfibrous coherent layer is formed on the film with the anchoringelements by the application in liquid form of a solidifiable substanceas a layer in the required thickness—preferably thicker than correspondsto the height of the projecting anchoring elements, even in the setstate. In the case of the embedded anchoring elements, it has to be soliquid that it penetrates at least partly into the voids. In the case ofthe projecting anchoring elements, it may be pasta-like or kneadable,for example a surfacing compound or kneading compound. A paste-likecompound is understood to be one with a Brookfield viscosity in therange from 20,000 to 1,000,000 mPas, as measured at the applicationtemperature of −100 to 300° C. and preferably −31 to 200° C.High-viscosity pastes may also be used, particularly for horizontalapplication. In their case, the viscosity is in the range from 2,000 to20,000 mPas. Compounds with viscosities of more than 1,000,000 mPas mayalso be used providing they can be incorporated in the anchoringelements, for example by kneading.

When the film is being coated with the anchoring elements, it is ofcourse important to ensure that the anchoring elements are not destroyedeither by mechanical forces or by melting where, for example, heatedcompounds, such as hotmelt adhesives, are applied.

The initially liquid nonfibrous layer sets and solidifies, such highcohesion being developed that the nonfibrous layer can be separatedintact and almost completely from the film despite the anchoringelements. This solid coherent layer is generally compact, but may alsobe porous.

The usual inorganic and organic binders are used including, for example,hydraulic binders (for example cement), lime mortar, gypsum, waterglass,polymer dispersions, polymer melts, polymer solutions, reactive one- ortwo-component polymer-based systems with the usual additives. Nonfibroussetting layers are plasters, lacquers, paints, road markings, PU foams,sealing compounds. Adhesives of any kind with which the substrates orelements can be joined, even without films, are preferred.

In the hardened state, the coherent nonfibrous layer is nonadhesive oronly slightly adhesive towards the film with the anchoring elements, theadhesion level amounting to at most 100% and preferably to at most 50%of the mechanical anchorage value. It is crucial that, when the layer issubsequently peeled off, its inner strength is higher than the sum ofthe adhesive strength and the mechanical anchorage.

The coherent nonfibrous layer is preferably an adhesive or containsbinders typical of adhesives, i.e. it joins the substrate to a surfacelayer.

The surface layer or the substrate is generally a protective ordecorative layer, for example wall, ceiling or floor coverings forbuildings or vehicles, for example wallpapers, inlaid floors, laminates,insulating boards, protective films, tiles, floor tiles, marble tiles,clay tiles, roof panels, carpets, pictures, shelves, panes of glass,bricks, coverings, claddings, etc.

The substrate may consist of masonry, plasters, concrete, screeds,surfacing fillers, metal, wood and plastic surfaces, tiles, glass.

The film seals the substrate in the usual way, depending on itsthickness and its constituent material. However, its permeability toair, water vapor and other gases may be improved by a certain porosity.

By virtue of these advantages, the invention is suitable for manyapplications of which some are mentioned by way of example in thefollowing drawings:

FIG. 6 is a schematic cross-section through a known composite material.The composite material contains the following layers:

-   a) decorative layer (3),-   b) adhesive layer (4),-   c) textile layer (5),-   d) film (2) with anchoring elements (1),-   e) adhesive layer (4) and-   f) substrate (6).

FIG. 7 is a schematic cross-section through a composite materialaccording to the invention of the following layers:

-   a) decorative layer (3),-   b) adhesive layer (4),-   c) film (2) with anchoring elements (1),-   d) adhesive layer (4) and-   e) substrate (6).

This composite material is typical of many applications in the domesticsector; the decorative layer may consist, for example, of wood blocks ortiles.

FIG. 8 is a schematic cross-section through a composite materialaccording to the invention comprising the following layers:

-   a) decorative layer (3),-   b) film (2) with anchoring elements (1) on both sides-   c) adhesive layer (4) and-   d) carpet as the fibrous substrate (6).

This composite material is typical of many applications where the setnonfibrous coherent layer is sufficient, for example plaster optionallyaugmented by a paint.

FIG. 9 is a schematic cross-section through an angled composite materialaccording to the invention consisting of

-   a) a joint sealing compound as the coherent layer (4),-   b) a film (2) with anchoring elements (1),-   c) an adhesive layer (4) and-   d) the substrate (6).

This composite material is particularly suitable for sealing gapsbetween walls and bathtubs because it seals very effectively in the longterm and because the joint sealing compound can be easily replaced whenits appearance has deteriorated.

FIG. 10 is a schematic cross-section through a composite materialaccording to the invention comprising relatively many layers, namely:

-   a) a covering (2) with anchoring elements (2),-   b) an adhesive (4),-   c) a film (2) with anchoring elements (1) on both sides,-   d) an adhesive (4) and-   e) a substrate (6) with anchoring elements (1).

This composite material is useful, for example, when the film withanchoring elements is to be joined on the one hand to the substrate andon the other hand to a covering with one and the same adhesive.

List of reference numerals

-   1 anchoring element-   2 film-   3 decorative layer-   4 adhesive layer or nonfibrous coherent layer-   5 textile layer-   6 substrate

1. A method of nondestructive, reversible fixing of a coherent layer toa substrate, comprising the steps of reversibly anchoring a nonfibrouscoherent layer to a film having either or both of projecting or embeddedanchoring elements by applying a liquid or paste form material to a sideof the film having the anchoring elements, which material embeds orfills the anchoring elements and sets to form the coherent layermechanically anchored to the film, wherein the anchoring elements willremain largely intact after separation of the coherent layer from thefilm, and fixing the coherent layer and film to the substrate.
 2. Themethod of claim 1, wherein the coherent layer is nonadhesive or onlyslightly adhesive to the film.
 3. The method of claim 1, wherein thefilm comprises or is coated with a material to which the coherent layershows very little or no adhesion.
 4. The method of claim 3, wherein filmcomprises or is coated with one or more polyolefins, silicone, orfluorine polymers.
 5. The method of claim 1, wherein the anchoringelements have a length of at least 0.05 mm.
 6. The method of claim 5,wherein the anchoring elements have a length of at least 0.2 mm.
 7. Themethod of claim 1, wherein one or more of the anchoring elements projectfrom the surface of the film.
 8. The method of claim 1, wherein thecoherent layer is peeled away from the film and the anchoring elementsare sufficiently deformable so that no more than 50% of the anchoringelements lose anchoring function after peeling of the coherent layerfrom the film.
 9. The method of claim 1, wherein the coherent layer ispeeled away from the film and the anchoring elements comprise asufficiently deformable material so that at least 30% of the anchoringelements retain anchoring function after peeling of the coherent layerfrom the film.
 10. The method of claim 9, wherein the anchoring elementscomprise a plastic having a glass transition temperature below 25° C.11. The method of claim 10, wherein the anchoring elements comprise aplastic having a glass transition temperature below 10° C.
 12. Themethod of claim 9, wherein the anchoring elements comprise polyethyleneor polypropylene.
 13. The method of claim 1, wherein the anchoringelements comprise mushroom-shaped elements projecting from the film,said elements having a cap and a stalk, wherein the cap and stalk have aratio of cross-sectional diameters of less than 10:1.
 14. The method ofclaim 1, wherein the coherent layer is peeled away from the film and thecoherent layer comprises a material that is sufficiently deformable sothat less than 50% of the anchoring elements lose anchoring functionafter peeling of the coherent layer from the film.
 15. The method ofclaim 1, wherein the anchoring elements comprise a material that isnondeformable or substantially nondeformable in the form of a thin layerwith a thickness of 0.05 mm to 10 mm.
 16. The method of claim 15,wherein the material comprising the anchoring elements is a resilientmaterial having less than 30% deformability.
 17. The method of claim 15,wherein the material comprising the anchoring elements is anon-resilient material having less than 15% deformability.
 18. Themethod of claim 1, wherein the anchoring elements comprise metal,ceramic, glass, or a thermoset or thermoplastic having a glasstransition temperature of at least 0° C.
 19. The method of claim 18,wherein the thermoset or thermoplastic has a glass transitiontemperature of at least 25° C.
 20. The method of claim 1, wherein theanchoring elements are shaped to slide out from the coherent layer whenit is peeled from the film.
 21. The method of claim 1, wherein thecoherent nonfibrous layer consists of a single layer.
 22. The method ofclaim 21, wherein the coherent nonfibrous layer consists of a plaster,paint, lacquer, sealing, road marking, or PU foam layer.
 23. The methodof claim 1, wherein the coherent nonfibrous layer comprises at least onelayer.
 24. The method of claim 23, wherein coherent nonfibrous layercomprises an adhesive layer.
 25. The method of claim 24, wherein theadhesive layer comprises an adhesive having a glass transitiontemperature below 25° C. in its set state.
 26. The method of claim 24,wherein the adhesive layer is based on a dispersion adhesive.
 27. Themethod of claim 23, wherein the coherent nonfibrous layer comprises asurface layer.
 28. The method of claim 27, wherein the surface layercomprises tile, wood, wall covering, or plastic molding.
 29. The methodof claim 1, wherein the film is fixed to the substrate by adhesives,nails, or screws.
 30. The method of claim 1, wherein the substrate is awall, ceiling, or floor of a building or motor vehicle.
 31. The methodof claim 1, wherein the film is mechanically fixed to the substrate byanchoring elements either directly or indirectly via a coherentnonfibrous layer.
 32. The method of claim 31, wherein the coherentnonfibrous layer fixing the film to the substrate comprises an adhesivelayer.
 33. The method of claim 32, wherein the adhesive layer fixing thefilm to the substrate adheres to the substrate at least 50% strongerthan to the coherent nonfibrous layer anchored to the film.
 34. Themethod of claim 33, wherein the coherent nonfibrous layer anchored tothe film and the adhesive layer fixing the film to the substratecomprise the same material.
 35. The method of claim 1, wherein the filmhaving the anchoring elements has holes making up at most 10% of itssurface.